Rapid diazotransfer for selective lysine labelling

Area of Science:

• Biochemistry
• Chemical Biology
• Molecular Biology

Background:

• Selective functionalization of proteins is crucial for introducing new functionalities.
• Bioorthogonal chemistry enables modification of biomolecules in native environments.
• Lysine residues are common targets for chemical modification.

Purpose of the Study:

• To develop an optimized method for azide functionalization of protein and peptide lysine residues.
• To achieve site-selective labeling under mild, aqueous conditions.
• To demonstrate the utility of azidolysine-modified proteins in bioorthogonal reactions.

Main Methods:

• Optimized diazotransfer reactions under mild, aqueous conditions (pH 8.5, 20 min).
• Modification of reaction conditions for selective labeling of single lysine residues.
• Copper(I)-catalyzed triazole formation for bioorthogonal conjugation.

Main Results:

• Efficient azide functionalization of amino acids, peptides, and proteins achieved.
• Selective labeling of a single lysine residue demonstrated in two protein targets.
• Successful bioorthogonal modification of proteins containing a single azidolysine.

Conclusions:

• The developed method provides a rapid and selective approach for protein and peptide azide functionalization.
• This technique allows for the introduction of specific functionalities at defined lysine sites.
• The azidolysine-modified proteins are readily utilized in bioorthogonal conjugation strategies, such as copper(I)-catalyzed triazole formation.